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Commit b8004afb authored by Vladimir Razgulin's avatar Vladimir Razgulin
Browse files

PM/devfreq: Add bw_vbif governor 



This governor should be used by KGSL driver to vote for msm bus
bandwidth using devbw devices.

KGSL driver needs to register a callback function that returns
required IB value, and call devfreq_vbif_update_bw() function
any time it want to vote for bus bandwidth.

Change-Id: I6c7c08b7c3255b3793f1868d9cde604175093145
Signed-off-by: default avatarVladimir Razgulin <vrazguli@codeaurora.org>
parent 10704daa

drivers/devfreq/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ obj-$(CONFIG_ARMBW_HWMON) += armbw-pm.o 
obj-$(CONFIG_DEVFREQ_GOV_MSM_BW_HWMON)	+= governor_bw_hwmon.o

obj-$(CONFIG_DEVFREQ_GOV_MSM_CACHE_HWMON)	+= governor_cache_hwmon.o

obj-$(CONFIG_DEVFREQ_GOV_MSM_GPUBW_MON)	+= governor_gpubw_mon.o

obj-$(CONFIG_DEVFREQ_GOV_MSM_GPUBW_MON)	+= governor_bw_vbif.o



# DEVFREQ Drivers

obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos4_bus.o

drivers/devfreq/governor_bw_vbif.c

0 → 100644
+129 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2014, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/devfreq.h>

#include <linux/module.h>

#include "governor.h"



unsigned long (*extern_get_bw)(void) = NULL;



DEFINE_MUTEX(df_lock);

static struct devfreq *df;



/*

 * This function is 'get_target_freq' API for the governor.

 * It just calls an external function that should be registered

 * by KGSL driver to get and return a value for frequency.

 */

static int devfreq_vbif_get_freq(struct devfreq *df,

				unsigned long *freq,

				u32 *flag)

{

	if (extern_get_bw) {

		*freq = extern_get_bw();

		return 0;

	} else {

		return -ENODEV;

	}

}



/*

 * Registers a function to be used to request a frequency

 * value from legacy vbif based bus bandwidth governor.

 * This function is called by KGSL driver.

 */

void devfreq_vbif_register_callback(void *p)

{

	extern_get_bw = p;

}





int devfreq_vbif_update_bw(void)

{

	int ret = 0;



	mutex_lock(&df_lock);

	if (df) {

		mutex_lock(&df->lock);

		ret = update_devfreq(df);

		mutex_unlock(&df->lock);

	}

	mutex_unlock(&df_lock);

	return ret;

}



static int devfreq_vbif_ev_handler(struct devfreq *devfreq,

					unsigned int event, void *data)

{

	int ret;



	switch (event) {

	case DEVFREQ_GOV_START:

		mutex_lock(&df_lock);

		df = devfreq;

		mutex_unlock(&df_lock);



		ret = devfreq_vbif_update_bw();

		if (ret) {

			pr_err("Unable to update BW! Gov start failed!\n");

			return ret;

		}

		/*

		 * Normally at this point governors start the polling with

		 * devfreq_monitor_start(df);

		 * This governor doesn't poll, but expect external calls

		 * of its devfreq_vbif_update_bw() function

		 */

		pr_debug("Enabled MSM VBIF governor\n");

		break;



	case DEVFREQ_GOV_STOP:

		mutex_lock(&df_lock);

		df = NULL;

		mutex_unlock(&df_lock);



		pr_debug("Disabled MSM VBIF governor\n");

		break;

	}



	return 0;

}



static struct devfreq_governor devfreq_vbif = {

	.name = "bw_vbif",

	.get_target_freq = devfreq_vbif_get_freq,

	.event_handler = devfreq_vbif_ev_handler,

};



static int __init devfreq_vbif_init(void)

{

	return devfreq_add_governor(&devfreq_vbif);

}

subsys_initcall(devfreq_vbif_init);



static void __exit devfreq_vbif_exit(void)

{

	int ret;



	ret = devfreq_remove_governor(&devfreq_vbif);

	if (ret)

		pr_err("%s: failed remove governor %d\n", __func__, ret);



	return;

}

module_exit(devfreq_vbif_exit);



MODULE_DESCRIPTION("VBIF based GPU bus BW voting governor");

MODULE_LICENSE("GPL v2");

include/linux/msm_adreno_devfreq.h

+5 −0
Original line number Diff line number Diff line
@@ -63,4 +63,9 @@ struct msm_busmon_extended_profile { 
	struct devfreq_dev_profile profile;

};



#ifdef CONFIG_DEVFREQ_GOV_MSM_GPUBW_MON

int devfreq_vbif_update_bw(void);

int devfreq_vbif_register_callback(void *);

#endif



#endif